Conventionally, as illustrated in FIG. 9, there is known an electromagnetic actuator (hereinafter referred to as a solenoid) for displacing a spool valve J1 which is a valving element of a spool control valve through a spool hole J3 of a sleeve J2 toward an adjust screw J4 (toward an opening of the spool hole J3) (see, for example, Korean patent application publication No. 10-2009-0084753). For this solenoid, there is known a solenoid including a plunger 101, a coil inner peripheral side fixed core (cylindrical stator cores 102, 103, magnetic resistance part 104), a coil outer peripheral side fixed core (cylindrical yoke 105 with a bottom), a coil 106, first and second terminals 107, 108, and a terminal holder 109 (see, for example, Korean patent application publication No. 10-2009-0084753).
The first terminal 107 is used as a coil terminal on the coil side having an internal joining part that is conduction-joined to an electric conductor (conducting wire) which is formed into the coil 106. The second terminal 108 is used as an outer side coil terminal having a tuning fork terminal that is fitted and connected to a tab terminal of a counterpart terminal, and an intermediate joining part that is conduction-joined to the terminal 107 by, for example, welding or crimping.
Points at issue of the conventional technology will be described below. In the conventional solenoid, the coil terminals have two divided structures of the first terminal 107 and the second terminal 108 which are integrated by a conduction joining means (e.g., welding or crimping). Accordingly, reliability in energization (conduction) of an internal connection part between the first terminal 107 and the second terminal 108 is not easily ensured.
An insertion hole 113 is formed through an outer surface (yoke upper surface 112) of a bottom wall portion 111 of the yoke 105. The terminal holder 109 is snap-fit joined to the yoke upper surface 112 such that an end part (snap fitting pawl part 115) of a resilient engagement piece 114 projecting from the terminal holder 109 toward the yoke is hooked on an engagement part 116 provided on an inner surface of the bottom wall portion 111 of the yoke 105. As above, since the method of fixing the terminal holder 109 to the yoke 105 is snap-fit joining, backlash is necessarily caused at a snap-fit joined portion. Because of this backlash of the snap-fit joining, there are caused a position shift of the internal connection part between the first terminal 107 and the second terminal 108, and a position shift of an external connection part between the second terminal 108 and the counterpart terminal. As a result, there is an issue that it is more difficult to ensure reliability in energization (conduction) at the internal connection part and the external connection part.